1. Field of the Invention
The present invention relates to a steering system.
2. Description of the Related Art
Steering systems are generally configured such that a steering member and a steering operation mechanism are mechanically coupled to each other at all times. In recent years, however, there have been proposed a variety of steering systems in which switching can be made between a coupled state in which a steering member and a steering operation mechanism are mechanically coupled to each other and a decoupled state in which the steering member and the steering operation mechanism are mechanically decoupled from each other, and in which a so-called steer-by-wire configuration is implemented in the decoupled state.
A rotation transfer device described in Japanese Patent Application Publication No. 2009-293679 (JP 2009-293679 A), for example, is incorporated in the steering system in which the steer-by-wire configuration is implemented. In the rotation transfer device, switching is made between the coupled state and the decoupled state by a two-way roller clutch in accordance with whether or not an electromagnetic coil is energized.
In recent years, it has been proposed to dispose a clutch mechanism such as the rotation transfer device described in JP 2009-293679 A around a worm wheel of a speed reduction device in the steering systems. In order to avoid interference between the two-way roller clutch or the electromagnetic coil and other components, however, it is necessary not to extend the space for the arrangement of the two-way roller clutch or the electromagnetic coil in the axial direction.